U.S. patent number 8,165,863 [Application Number 12/547,015] was granted by the patent office on 2012-04-24 for visualization method for electrical machine operation models based on mechanical machine operation models.
This patent grant is currently assigned to Siemens Corporation. Invention is credited to Rainer Heller, Oswin Noetzelmann, Dirk Schaumburg.
United States Patent |
8,165,863 |
Noetzelmann , et
al. |
April 24, 2012 |
Visualization method for electrical machine operation models based
on mechanical machine operation models
Abstract
A visualization of an electrical machine operation model of
logic controller behavior is displayed on a display such as a
two-dimensional computer display. The display includes separate
spaces representing separate devices in the model. For each device,
several characteristics are shown in the model, including
mechanical steps, electrical steps and electrical signal outputs.
The electrical steps are shown superimposed on the mechanical
steps, and electrical transitions link sequential electrical steps
in time. Representations of conditions link the electrical
transitions with signal outputs upon which the electrical
transitions are conditioned.
Inventors: |
Noetzelmann; Oswin (Monmouth
Junction, NJ), Heller; Rainer (Eckental, DE),
Schaumburg; Dirk (Friedberg, DE) |
Assignee: |
Siemens Corporation (Iselin,
NJ)
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Family
ID: |
41261908 |
Appl.
No.: |
12/547,015 |
Filed: |
August 25, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100063792 A1 |
Mar 11, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61095997 |
Sep 11, 2008 |
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Current U.S.
Class: |
703/13 |
Current CPC
Class: |
G05B
19/05 (20130101); G05B 2219/13147 (20130101); G05B
2219/13144 (20130101) |
Current International
Class: |
G06F
17/50 (20060101) |
Field of
Search: |
;703/13 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 177 396 |
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Feb 2001 |
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EP |
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2009/105797 |
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Sep 2009 |
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WO |
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Other References
European Search Report dated Dec. 18, 2009. cited by other.
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Primary Examiner: Craig; Dwin M
Assistant Examiner: Louis; Andre Pierre
Parent Case Text
Claim of Priority
This application claims priority to, and incorporates by reference
herein in its entirety, pending U.S. Provisional Patent Application
Ser. No. 61/095,997, filed Sep. 11, 2008, and entitled
"Visualization Method for Electrical-Machine-Operation-Models Based
on Mechanical-Machine-Operation-Models," and is related to U.S.
patent application Ser. No. 12/546,987, filed on the same date as
the present application and entitled "Automated Derivation of a
Logic-Controller-Behavior-Model from a
Mechanical-Machine-Operation-Model."
Claims
What is claimed is:
1. A method for visually representing an electrical machine
operation model on a display space, the method comprising; (A)
using a computer connected to a display, apportioning the display
space into device subspaces, each subspace corresponding to a
different device represented by the electrical machine operation
model; (B) for each device subspace, using a common time axis for
all subspaces, performing the following for a represented device:
(1) creating a first region for displaying sequence information;
(2) creating a second region for displaying signal information; (3)
in the first region, displaying a representation of mechanical
device movement including mechanical steps of the represented
device as a function of time; (4) in the first region,
superimposing over the representation of mechanical device
movement, representations of electrical steps, each representation
of an electrical step overlaying a corresponding representation of
a mechanical step, each electrical step representing information
about plural sensor and actuator signals during a time period and
derived from the mechanical model; and (5) in the second region,
displaying representations of electrical signal values of
electrical signals associated with the represented device as a
function of time; and (C) for all device subspaces collectively,
performing the following: (1) connecting each pair of electrical
step representations that are sequential in time, with a graphical
connection representing an electrical transition in which a state
of the plural sensor and actuator signals changes from that of an
earlier electrical step to that of a later electrical step; and (2)
for at least one representation of an electrical transition,
displaying at least one representation of a condition graphically
connecting the representation of the electrical transition with one
of the representations of electrical signal values upon which the
transition is conditioned.
2. The method of claim 1, wherein the device subspaces are
horizontal partitions of the display space.
3. The method of claim 2, wherein time is represented in the
display space as a horizontal axis.
4. The method of claim 1, wherein the representation of mechanical
device movement in the display space is a series of connected line
segments, each segment representing a mechanical step.
5. The method of claim 4, wherein at least one mechanical step is
represented by a line segment having end points representing real
device positions.
6. The method of claim 5, wherein the line segment has at least one
intermediate point representing a real device position.
7. The method of claim 1, wherein the representation of a condition
is a line connecting an electrical transition with a point on a
representation of an electrical signal.
8. The method of claim 1, wherein the representation of an
electrical signal includes a transition between two sensor states
at a point on the common time axis.
9. The method of claim 1, further comprising the following for all
device subspaces collectively: (3) adding interlock information by
creating additional conditions.
10. The method of claim 1, further comprising the following for all
device subspaces collectively: (3) adding signal output values to
one or more electrical steps.
11. The method of claim 1, further comprising the following for all
device subspaces collectively: (3) changing an order in which the
device subspaces appear in the display, based on an interactive
user input to the computer.
12. The method of claim 1, further comprising the following for all
device subspaces collectively: (3) changing a condition by changing
one of the associated electrical transition and the representation
of an electrical signal, based on an interactive user input to the
computer.
13. The method of claim 1, further comprising the following for all
device subspaces collectively; (3) blending out of the display all
representations of a type selected from the group consisting of: a
representation of a mechanical device movement, a representation of
an electrical step, a representation of an electrical signal value,
a representation of an electrical transition, and a representation
of a condition.
14. A non-transitory computer-usable medium having computer
readable instructions stored thereon for execution by a processor
to perform a method for visually representing an electrical machine
operation model on a display space, the method comprising: (A)
apportioning the display space into device subspaces, each subspace
corresponding to a different device represented by the electrical
machine operation model; (B) for each device subspace, using a
common time axis for all subspaces, performing the following for a
represented device: (1) creating a first region for displaying
sequence information; (2) creating a second region for displaying
signal information; (3) in the first region, displaying a
representation of mechanical device movement including mechanical
steps of the represented device as a function of time; (4) in the
first region, superimposing over the representation of mechanical
device movement, representations of electrical steps, each
presentation of an electrical step overlaying a corresponding
representation of a mechanical step, each electrical step
representing information about plural sensor and actuator signals
during a time period and derived from the mechanical model; and (5)
in the second region, displaying representations of electrical
signal values of electrical signals associated with the represented
device as a function of time; and (C) for all device subspaces
collectively, performing the following: (1) connecting each pair of
electrical step representations that are sequential in time, with a
graphical connection representing an electrical transition in which
a state of the plural sensor and actuator signals changes from that
of an earlier electrical step to that of a later electrical step;
and (2) for at least one representation of an electrical
transition, displaying at least one representation of a condition
graphically connecting the representation of the electrical
transition with one of the representations of electrical signal
values upon which the transition is conditioned.
15. The non-transitory computer-usable medium of claim 14, wherein
the device subspaces are horizontal partitions of the display
space.
16. The non-transitory computer-usable medium of claim 15, wherein
time is represented in the display space as a horizontal axis.
17. The non-transitory computer-usable medium of claim 14, wherein
the representation of mechanical device movement in the display
space is a connected series of line segments, each segment
representing a mechanical step.
18. The non-transitory computer-usable medium of claim 17, wherein
at least one mechanical step is represented by a line segment
having end points representing real device positions.
19. The non-transitory computer-usable medium of claim 18, wherein
the line segment has at least one intermediate point representing a
real device position.
20. The non-transitory computer-usable medium of claim 14, wherein
the representation of a condition is a line connecting an
electrical transition with a point on a representation of an
electrical signal.
21. The non-transitory computer-usable medium of claim 14, wherein
the representation of an electrical signal includes a transition
between two sensor states at a point on the common time axis.
22. The non-transitory computer-usable medium of claim 14, wherein
the method further comprises the following for all device subspaces
collectively: (3) adding interlock information by creating
additional conditions.
23. The non-transitory computer-usable medium of claim 14, wherein
the method further comprises the following for all device subspaces
collectively: (3) adding signal output values to one or more
electrical steps.
24. The non-transitory computer-usable medium of claim 14, wherein
the method further comprises the following for all device subspaces
collectively: (3) changing an order in which the device subspaces
appear in the display, based on an interactive user input to the
computer.
25. The non-transitory computer-usable medium of claim 14, wherein
the method further comprises the following for all device subspaces
collectively: (3) changing a condition by changing one of the
associated electrical transition and the representation of an
electrical signal, based on an interactive user input to the
computer.
26. The non-transitory computer-usable medium of claim 14, wherein
the method further comprises the following for all device subspaces
collectively: (3) based on an interactive user input to the
computer, blending out of the display all representations of a type
selected from the group consisting of: a representation of a
mechanical device movement, a representation of an electrical step,
a representation of an electrical signal value, a representation of
an electrical transition, and a representation of a condition.
Description
FIELD OF THE DISCLOSURE
The present invention relates generally to the modeling of factory
behavior for the purpose of factory automation. More specifically,
the invention relates to techniques for visualizing an electrical
machine operation model of logic controller behavior while also
taking into account a model of mechanical machine operation on
which the electrical machine operation model is based.
BACKGROUND
In the automation field, and more specifically during operational
machine planning for a plant, an engineer traditionally creates a
model that describes which machines will later be involved in the
plant operation phase. Referring to FIG. 1A, the mechanical machine
operation model 120 contains a detailed description of each step
that each machine 115 performs in the operational process, as well
as how those steps interact. The model is traditionally created in
the form of a sequence diagram that shows machine behavior over
time in a graphical format. Today, software tools provide
meta-models for describing mechanical machine operation models and
allow convenient graphical creation and editing of those mechanical
models.
In order to program digital controllers to operate the machines,
the mechanical machine operation model 120 is traditionally given
to an engineer that is familiar with programmable logic controller
(PLC) programming and he or she abstracts the mechanical model at
125 and creates at 127 a PLC program 128 that realizes the
requirements described in the mechanical model 120. For example,
the logic may include logic for starting/stopping signals for the
machines in the correct timing, as well as safety critical features
such as interlocks and timeout detection. The engineer typically
adds sensors and actuators to the mechanical information as those
are often missing in the mechanical model as provided to the
engineer.
The abstraction of the mechanical model depends on the programming
method the engineer chooses. Examples of methods for programming a
PLC include STL (an assembler like language for Siemens PLCs),
Ladder Logic and Step Chain Programming, the most advanced of the
three. If a user chooses STL, the user must do the most abstraction
since he must formulate a program with only basic instructions. For
ladder logic, the user is assisted by a ladder diagram visual
display of the logic. For step chain programming, the user must
identify the steps in the program based on the mechanical
description (i.e., the sequence diagram) and determine the exact
sequence of the steps in the PLC, as well as identify the need for
input signal conditions.
In each case, those traditional systems may be error-prone due to
the required manual abstraction and the complexities faced by the
engineer, and may be time-consuming for the same reasons. There is
therefore presently a need for an improved technique of abstraction
for use in formulating a PLC program from a mechanical machine
operation model.
SUMMARY OF THE INVENTION
The present invention addresses the needs described above by
providing, in one embodiment, a method for visually representing an
electrical machine operation model on a display space. Using a
computer connected to a display, the display space is apportioned
into device subspaces, each subspace corresponding to a different
device represented by the electrical machine operation model. For
each device subspace, using a common time axis for all subspaces,
the following steps are performed for a represented device: (1) a
first region is created for displaying sequence information; (2) a
second region is created for displaying signal information; (3) in
the first region, a representation of mechanical device movement is
displayed, including mechanical steps of the represented device as
a function of time; (4) in the first region, representations of
electrical steps are superimposed over the representation of
mechanical device movement, each electrical step overlaying a
corresponding mechanical step; and (5) in the second region,
representations are displayed of electrical signal values of
electrical signals associated with the represented device as a
function of time. For all device subspaces collectively, the
following steps are then performed: (1) each pair of electrical
step representations that are sequential in time are connected,
with a connection representing an electrical transition; and (2)
for at least one representation of an electrical transition, at
least one representation is displayed of a condition associating
the electrical transition with a representation of an electrical
signal.
Another embodiment of the invention is a computer-usable medium
having computer readable instructions stored thereon for execution
by a processor to perform methods as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic diagram showing a prior art PLC program
creation process.
FIG. 1B is a schematic diagram showing a PLC program creation
process in accordance with the present disclosure.
FIG. 2 is a sequence diagram showing an exemplary mechanical model
in accordance with the present disclosure.
FIG. 3 is a schematic view showing the division of a display space
into subspaces, according to the present disclosure.
FIG. 4 is a schematic view of one subspace of a display space
according to the invention.
FIG. 5 is a schematic view of the subspace of FIG. 4 showing a
model visualization according to the present disclosure.
FIG. 6 is a schematic view of another display space showing a model
visualization according to the present disclosure.
FIGS. 7A-7D are schematic views showing selective collapsing of
subregions of the visualization according to the present
disclosure.
FIG. 8 is a schematic view showing a system according to the
present disclosure.
DESCRIPTION
Disclosed herein is a new technique for the visualization of an
electrical machine operation model for use in formulating a PLC
program from a mechanical machine operation model. The electrical
model may be derived automatically or semi-automatically from a
mechanical model. The electrical machine operation model
streamlines and improves the efficiency of the engineering process
that is used in the automation field to create PLC (Programmable
Logic Controller) programs that control machines in a manufacturing
plant, a factory, etc.
As shown in FIG. 1B, the electrical machine operation model 164 for
which a visualization technique is disclosed herein may be used in
an automatic generation process 150 for target-system-specific PLC
programs 168. The process begins with a mechanical machine
operation model 160 containing descriptions of each step performed
by each machine 155, as well as how those steps interact. Using an
automated or partially automated derivation process 162, the
intermediate electrical machine operation model 164 is produced.
The electrical machine operation model is visualized using the
methods and systems described in the present disclosure. PLC
runtime software 168 may then be automatically generated at 166
from the electrical machine operation model 164. The runtime
software 168 is specifically targeted to the system used in
controlling the plant. The electrical machine operation model may
be modified manually at 170, using the presently described
visualization technique, to add information such as interlocks and
additional signal input conditions as well as signal outputs.
Electrical Machine Operation Model
The electrical machine operation model may be seen as a model that
is between a PLC program and a mechanical machine operation model
or sequence graph. Like the PLC program and mechanical machine
operation model, it is a directed, non-circular graph where the
nodes are called steps and the edges are called transitions.
To illustrate the technique for visualizing an electrical machine
operation model as disclosed herein, an underlying mechanical
machine operation model 200 will first be described with reference
to FIG. 2. In FIG. 2, machines or devices are represented by a row
in a chart, including the row 210 representing a pusher and the row
220 representing a lifter. The model also includes operational
steps and transitions between the steps, shown as timing behavior
in rows 210, 220 along a horizontal time line 230.
A mechanical step describes a change in the state of the machine.
The state may, for example, be a physical position. Because a
change in a state often represents a change in physical position, a
state is often referred to as a "position." The changes in position
are described in the timing behavior of the model. In the example
model 200, the pusher represented in row 210 moves from a "back"
position to a "front" position in step 262, remains in the "front"
position during a waiting period 264, moves from the "front"
position to the "back" position in step 266, and remains in the
"back position during the waiting period 268. Changes in the
position of the lifter between "up" and "down" are similarly
represented in row 220.
In its simplest form, a mechanical machine operation model
identifies only the start and end positions defining a change in
position. The exact physical behavior between the start and end
points, including intermediate positions, velocity and
acceleration, is not described in the simplest case. For example,
the straight line segments representing steps 262 and 266 do not
represent information about the behavior of the devices between the
start and end points of the steps. An expanded mechanical machine
operation model, however, may accommodate such information. The
information about the changes in position as well as the connected
timing behavior can be grouped into an operation type--also called
an "action." In sum, devices can perform actions, and each
performance of an action is called a step.
The sequence of steps is defined by transitions. For example, the
timing behavior of the pusher 210 includes a transition 272 between
step 262 and step 264, a transition 274 between the waiting period
264 and step 266, and a transition 276 between step 266 and the
waiting period 268.
The electrical machine operation model is based on the mechanical
model. It also includes steps and transitions, but does not include
actions. The steps of the electrical machine operation model may
additionally include so-called waiting steps wherein a user can add
waiting times in the electrical model. The transitions of the
electrical machine operation model may be very different from those
of the mechanical model, because it is possible for a user to
represent one mechanical sequence with multiple electrical
sequences. For example, a user may define one electrical sequence
per device. An important difference between the electrical machine
operation model and the mechanical model is the fact that the
electrical machine operation model has information about electrical
(sensor and actuator) signals. The electrical machine operation
model stores conditions for those signals on transitions that are
between electrical steps.
To create the electrical machine operation model, an engineer must
define sensor signals associated with a machine. Those signals are
logically connected to a mechanical position. For example, in the
system shown in the diagram 200 of FIG. 2, when the pusher of row
210 completes step 262 and arrives at transition 272, a sensor
signal, represented by arrow 252, is generated. That signal 252
satisfies a condition for the lifter of row 220 to leave transition
292 and perform step 282. Similarly, when the lifter of row 220
completes step 282 and arrives at transition 294, a sensor signal,
represented by arrow 254, is generated. That signal 254 satisfies a
condition for the pusher of row 210 to leave transition 274 and
perform step 266.
As described below, the electrical machine operation model is
created by creating electrical elements corresponding to the
mechanical steps, signals and conditions. Electrical steps can also
have interlock information, as well as additional signal output
values. Those parameters may be added manually by an engineer using
the visualization technique described herein.
The electrical machine operation model therefore includes
electrical steps, transitions between the electrical steps,
signals, conditions that store values for specific signals, signal
output information and interlock information.
Visualizing the Electrical Machine Operation Model
Disclosed herein is a technique for visualizing the electrical
machine operation model that reduces the amount of abstraction
necessary for an engineer working with the transition of mechanical
to electrical information. The visualization technique provides the
engineer with information about the mechanical behavior as well as
the resulting electrical behavior at the same time, without
becoming unclear or obscure.
Embodiments of the invention provide methods, systems, and a
computer useable medium storing computer-readable instructions for
visualizing an electrical machine operation model. The invention
may be implemented as a modular framework and deployed as software
as an application program tangibly embodied on a program storage
device. The application code may reside on a plurality of different
types of computer readable media known to those skilled in the
art.
Visualization may be performed on a two-dimensional (or
three-dimensional) display space such as that of a computer or
video display. The display may be part of a graphical user
interface that may also include a keyboard, a mouse or other user
interface devices, for interfacing with a computer. The display is
controlled by one or more computers running one or more application
programs for performing the described visualization methods.
In the following, the visualization concept is explained step by
step by means of the concept drawings of FIGS. 3-6, showing various
stages of an exemplary visualization. In the display space 300 of
FIG. 3, a horizontal axis 305 represents time, as is the case in a
traditional sequence diagram. The single time axis 305 is used in
common by all elements of the visualization. Although shown as a
horizontal axis, the time axis 305 may extend in another direction,
such as the vertical direction.
The space 300 is divided into a plurality of subspaces including
subspace 310 and subspace 320. Each of the subspaces 310, 320
represents a device or machine that is an element of the mechanical
machine operation model upon which the visualization is based. Each
of the subspaces 310, 320 utilizes the single time axis 305 in
representing machine sequence information. The device subspaces
310, 320 are placed in a group 308 by their affiliation to a
particular electrical sequence. Additional subspaces (not shown)
that are affiliated with the same electrical sequence are placed in
the same group as subspaces 310, 320. Other device subspaces (not
shown) affiliated with another electrical sequence are separately
grouped.
The subspace 310 of the space 300, shown in more detail in FIG. 4,
includes a device header space 309 for indicating the particular
device described in the subspace. In the subspace 310, a first
region 311 is created for displaying sequence information of the
particular device, and a second region 315 is created for
displaying signal information of the particular device. All
important information (mechanical positions, steps, signals, signal
values) for the particular device may thereby be integrated in the
subspace 310. The first region 311 is additionally subdivided into
a subregion 312 for defining the mechanical positions of the device
as positions on a vertical axis, and a subregion 313 for depicting
the sequence information for the device, including steps and
transitions. The sequence information is depicted along the common
timeline 305 (FIG. 3), beginning at a timeline reference starting
point 306. The sequence may, for example, start at a timeline zero
point, or may start at a particular time of day. For longer
sequences, the subregion 313 may be scrolled left or right to view
additional portions of the sequence. The second region 315 is
subdivided into a subregion 316 for defining states of the
electrical signals of the device as locations on a vertical axis,
and a subregion 317 for depicting the signal information for the
device.
As shown in FIG. 5, an exemplary electrical sequence, together with
corresponding mechanical operations and the corresponding
electrical signal values, are visualized in the device subspace 310
of space 300 for a particular device identified in the device
header space 309.
An underlying mechanical machine operation model is represented in
the region 311. The subregion 312 has been populated by four device
positions 511-514 defined by four points along the vertical axis.
The mechanical model, represented in subregion 313, includes
operational steps 521, 522, 523 and transitions 525, 526 between
the steps, which together represent timing behavior along the
common horizontal time line having a zero point 306.
The example device represented in subspace 310 moves from position
512 to position 511 in step 521, then moves from position 511 to
position 514 in step 522, and then moves from position 514 to
position 513 in step 523.
Superimposed on the mechanical machine operation model are the
electrical steps 531, 532, 533 of the electrical machine operation
model. The connecting lines 535, 536 represent electrical
transitions. In the diagram of FIG. 5, it can be seen that for each
mechanical step 521, 522, 523 in the mechanical model, an
electrical step 531, 532, 533 was created in the electrical machine
operation model. For example, for the mechanical step 521, in which
the device moves from position 512 to position 511, the
corresponding electrical step 531 is created.
Additional information may be superimposed on the electrical steps.
For example, the electrical steps 531, 532, 533 may include
superimposed text 561, 562, 563 listing the step number, the step
order in the particular sequence, and the assignment of steps or
sequences to PLC-program blocks/modules.
For each mechanical transition on a particular step in the
mechanical model, a corresponding electrical transition is created
on the corresponding electrical step in the electrical model. For
example, the electrical transition 535 is created on the electrical
step 521 to correspond to the mechanical transition 525 on the
mechanical step 521. The electrical transition 536 is similarly
created to correspond to mechanical transition 526 of the
mechanical model.
The representation of the device of subspace 310 also includes, in
region 315, representations of sensor signals 551, 552, 553, 554.
Each sensor is labeled in the subregion 316, and the sensor signals
are represented in subregion 317. The sensor signals are
represented using the time axis and timeline reference starting
point 306 in common with the mechanical and electrical steps and
transitions shown in region 311. States of the sensors, such as
high/low, true/false and analog values, are defined by levels on
the vertical axis.
The signals may be associated with a mechanical state/position of
the device. The signal 551, for example, is associated with the end
position of the mechanical step 521, wherein the device moves to
position 511. In another example, the signal 554 is associated with
the end position of the mechanical step 522, wherein the device
moves to position 514.
The visualization of the electrical machine operation model shown
in FIG. 5 also includes representations of conditions 540, 541 on
the electrical transitions 535, 536. A condition makes an
electrical transition conditional on a signal associated with an
end position of the underlying mechanical step. For example, the
condition 540 is created on the electrical transition 535 for the
signal 551. In the embodiment shown in FIG. 5, the condition is
represented by an arrow extending from the electrical transition
535 to a point 561 where the signal 551 becomes "true" or "high."
One skilled in the art will recognize that a transition may also be
conditioned on a signal becoming "false" or "low," as signal 552
does during the electrical transition 535.
The condition 540 requires that the electrical transition 535
cannot take place until the signal 551 becomes "true." In
mechanical terms, the condition 540 requires that the described
device be in position 511, as indicated by the signal 551, before
the device begins the mechanical step of moving from position 511
to position 514.
Similarly, the condition 541 is created on the electrical
transition 536 for the signal 554, requiring that the device be in
position 514, as indicated by the signal 554, before the device
begins the mechanical step of moving from position 514 to position
513.
The electrical machine operation model visualized by the technique
of the present disclosure may be used in automatically or
semi-automatically generating PLC software for use in an industrial
application. While the intermediate electrical machine operation
model is in a format that is independent of any proprietary or
other PLC-specific language, the PLC software generated from that
model may be generated in any format required by any particular
PLC.
The visualization technique of the present disclosure permits the
engineer to change or edit the conditions to evaluate alternatives.
For example, the condition 540, shown in FIG. 5, may be edited by a
user to make the electrical transition 535 conditional on the
signal 552 becoming "low" instead of, or in addition to, the signal
551 becoming "high." The edited electrical machine operation model
may then be evaluated and compared to the original electrical
machine operation model, and a decision may be made whether to make
the change permanent.
Multiple devices and their interrelationships may be visualized in
a single space using the disclosed technique. For example, the
display space 600, shown in FIG. 6, is divided into subspaces 610,
620. A device identified in the device header space 609 is
represented in the subspace 610, and a device identified in the
device header space 619 is represented in the subspace 620.
The device representation of subspace 610 includes two mechanical
steps 611, 613. The electrical step 612 is superimposed on the
underlying mechanical step 611, from which it was created.
Similarly, the electrical step 614 is superimposed on the
underlying mechanical step 613, from which it was created. The
device representation of subspace 610 also includes signal
representations, including a representation of signal 615, which
becomes "high" after completion of the mechanical step 611.
The device representation of subspace 620 includes a mechanical
step 621. The electrical step 622 is superimposed on the underlying
mechanical step 621, from which it was created. The device
representation of subspace 620 also includes signal representations
including a representation of signal 625, which becomes "high"
after completion of the mechanical step 621.
Unlike the electrical transitions of space 300 (FIG. 5), the
electrical transitions 630, 631 shown in the space 600 (FIG. 6)
connect electrical steps performed by different devices. For
example, the electrical transition 630 connects the electrical step
612, performed by the device identified in the device header space
609, with the electrical step 622, performed by the device
identified in the device header space 619. Similarly, the
electrical transition 631 connects the electrical step 622 with the
electrical step 614, performed by the device identified in the
device header space 609.
Conditions are shown for each of the electrical transitions. The
condition 640 makes the transition 630 conditional on the signal
615, while the condition 641 makes the transition 631 conditional
on the signal 625. It can be seen that conditions may be
represented in the space 600 whereby any transition may be made
conditional on any related signal, regardless of the device with
which the signal is associated. The conditions may be interactively
changed by a user, for example, by dragging with a mouse, in order
for a user to evaluate various configurations. While the
transitions are shown conditional on changes in digital signal
values, the transitions may alternatively be triggered by an analog
signal reaching a threshold value.
While the space 600 contains only two subspaces 610, 620
representing two devices, a typical space contains more than two
subspaces and may show a complex factory system containing a large
number of subspaces representing a large number of machines. In
accordance with one aspect of the invention, the individual devices
as well as groups of devices may be reordered using a "drag and
drop" graphical user interface technique, or other user interface
techniques. In that way, machines may be reordered or regrouped in
different electrical sequences to alter or to better show
interrelationships.
In one embodiment, the overall visual complexity of a visualization
may be reduced by selectively blending out certain parts of the
visualization, such as condition connectors, transition lines or
whole electrical sequences. That feature is particularly useful
where large numbers of devices and steps make the visualization
difficult to read. Certain features may then be blended in as
needed to view the display. Color-coding may also be used to more
easily identify features in the visualization. For example, the
display may be color-coded according to type of feature, such as a
mechanical step, an electrical transition, a condition, etc.
Alternatively, each device and its associated elements may be
visualized in a different color, to better relate conditions to the
devices they affect.
In one embodiment, regions of the display space containing
information about one or more devices may be selectively collapsed.
For example, referring to FIG. 7A, a region 711 displays
information about device 1, including device positions and
movements shown in subregions 712, 713, and device sensors and
signals shown in subregions 716, 717. A user may selectively
collapse the movement area of region 711, including subregions 712,
713, so that only the signal areas 716, 717 are displayed, as shown
in FIG. 7B. A user may alternatively collapse the signal area
display, including subregions 716, 717, so that only the movement
areas 712, 713 are displayed, as shown in FIG. 7C. The entire
region 711 may also be collapsed, as shown in FIG. 7D. By
selectively collapsing subregions, the user may reduce the overall
visual complexity of the visualization.
The present invention may be embodied in a system for visualizing
an electrical machine operation model. FIG. 8 illustrates a system
800 for visualizing an electrical machine operation model according
to an exemplary embodiment of the present invention. As shown in
FIG. 8, the system 800 includes a personal or other computer (PC)
810 and an operator's console 815. The system may be connected to
one or more PLCs 806 over a wired or wireless network 805.
The PC 810, which may be a portable or laptop computer or a
mainframe or other computer configuration, includes a central
processing unit (CPU) 825 and a memory 830 connected to an input
device 850 and an output device 855. The CPU 825 includes a model
visualization module 845 and that includes one or more methods for
visualizing an electrical machine operation model as discussed
herein. Although shown inside the CPU 825, the model visualization
module 845 can be located outside the CPU 825.
The memory 830 includes a random access memory (RAM) 835 and a
read-only memory (ROM) 840. The memory 830 can also include a
database, disk drive, tape drive, etc., or a combination thereof.
The RAM 835 functions as a data memory that stores data used during
execution of a program in the CPU 825 and is used as a work area.
The ROM 840 functions as a program memory for storing a program
executed in the CPU 825. The program may reside on the ROM 840 or
on any other computer-usable medium as computer readable
instructions stored thereon for execution by the CPU 825 or other
processor to perform the methods of the invention. The input 850 is
constituted by a keyboard, mouse, network interface, etc., and the
output 855 is constituted by a liquid crystal display (LCD),
cathode ray tube (CRT) display, printer, etc.
The operation of the system 800 can be controlled from the
operator's console 815, which includes a controller 865, e.g., a
keyboard, and a display 860. The operator's console 815
communicates with the PC 810 and through a network, a bus or other
means so that a visualization created by the module 845 can be
rendered by the PC 810 and viewed on the display 860. The PC 810
can be configured to operate and display information by using,
e.g., the input 850 and output 855 devices to execute certain
tasks. Program inputs, such as a mechanical machine operation
model, may be input through the input 850 or may be stored in
memory 830.
Conclusion
The visualization technique described herein provides for improved
electrical machine operation planning. For example, the model is
more easily understandable by a user because the visualizations of
electrical steps for all devices are in the correct timing and are
shown in connection with corresponding mechanical behavior. The
model is also made clearer by the visualization of electrical
signal conditions and their association with the electrical
transitions between the steps, and by the visualization of expected
signal values and conflicts in those expectations.
While the described visualization technique can help an engineer
when drawn manually, a computer implemented version of the
technique may be enhanced with several useful features. For
example, interactive changes may be made to the model, such as
changing the condition values. Complexity may be reduced by
selective blend out or blend in of certain parts such as condition
connectors or transition lines. Features such as devices and
sequences may easily be reordered through drag and drop or other
computer graphical user interface techniques. Algorithms may be
used to simplify and/or automate parts of the creation of the
electrical or mechanical model. Real-time machine process
monitoring in the operational phase of a plant may be incorporated
into the same view.
The present invention provides a tool that permits visualization of
all important aspects of electrical machine planning for a plant in
a single drawing. Less abstraction is therefore required, leading
to the faster design of PLC programs. The clearer visualization
helps to identify errors in earlier stages of the development and
thus reduces testing time and effort. It is expected that work-in
time for an existing machine operation processes will be reduced if
plans with the new visualization technique exist.
The foregoing Detailed Description is to be understood as being in
every respect illustrative and exemplary, but not restrictive, and
the scope of the invention disclosed herein is not to be determined
from the Description of the Invention, but rather from the Claims
as interpreted according to the full breadth permitted by the
patent laws. It is to be understood that the embodiments shown and
described herein are only illustrative of the principles of the
present invention and that various modifications may be implemented
by those skilled in the art without departing from the scope and
spirit of the invention.
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